


Pseudo-Servant Mayhem

by Aberron



Category: Fate/stay night & Related Fandoms
Genre: Multi
Language: English
Status: Completed
Published: 2019-12-10
Updated: 2019-12-10
Packaged: 2021-02-25 21:27:46
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,854
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21742195
Author URL: https://archiveofourown.org/users/Aberron/pseuds/Aberron
Summary: Shinji Matou finally learns some magic. The aftereffects of this cascade across all of Fuyuki, leading to some very awkward results. Crack AU.
Kudos: 38





	Pseudo-Servant Mayhem

Zouken was having one of those kinds of days. Where being corporeal was more of a chore than an accomplishment. "I want to learn magic!" Shinji begged. "I've spent years in your library, reading the basics. I've listened to you whenever you speak!" The boy was useless, it was true. Zouken knew it. The boy would eventually know it. But until then he prattled onwards.

"You wouldn't be able to hold you own against a true mage even if I enhanced your abilities." Zouken muttered. "I've tried this in the past."

"What happened?" Shinji asked, daring to know more. He decided to screw with the boy's head.

"Your father drank himself to death trying to forget." Shinji turned a color more akin to puce. His hair was still the blue of his father. When Byakuya was a child Zouken had tried his best to implant leftover from the experiment, so that was a sign that it succeeded. "Of course, a true mage has no fear of the unknown."

"I am a Matou!" Shinji muttered to himself. "Even if I have to find magic elsewhere and bring it back here, I will still become a magus!"

Shinji was about to storm out when Zouken remembered. He had a cruel and bitter idea long ago, and perhaps it was time to try it. Sakura was old enough now that it would be at least worth it to interrupt the plans of the other forces of Heaven's Feel. Especially when that black mud was terrifying enough. Better to waste Shinji experimenting on this. If it worked, he would hand out instructions for how to do it to those who could not refuse. "Shinji." He stated. "If you wish to become a Magus, you can attempt the ritual that drove your father insane. I have had twenty years to perfect it, and it should work better this time. You are twice the man your father was," on a negative scale, "so you should be better for it."

The boy slid on his knees in front of Zouken. "Thank you grandfather!"

"To the basement."

The boy's thanks died on his lips, and yet, he still followed him down into the dank cellar. Zouken spent some time searching, tossing aside dusty tomes and crumbling boxes. He found his goal sitting next to his commemorative collectors edition of the Sailor Moon manga, and the ashes of Ivan the Terrible, two wonderful inspirations of his. With a wave of his hand a Grail War circle formed, and he dragged Shinji inside. Sakura was watching from the stairs, curious to see someone else go into the pit for a change. "I'll carve the necessary symbols onto your hand myself."

"Will this leave a scar?"

"Shall I carve it into your face?"

Shinji gulped and held out his hand. Odd that he found himself a spine. If only he had inborn magic circuits worthy of a mage. Zouken made a few shallow cuts into the boy's hand, a wave of slime and ooze from a worm keeping them open but not bleeding everywhere. "Now, Shinji, hold your hand over this altar, and this ancient piece of statuary. Then read what is in the book."

Shinji read it over. "Grandpa, is this a Henshin chant?"

"Read it." He said coldly. "Succeed where your father failed."

Byakuya never went to the basement after Zouken tried to implant magic circuits from dead victims into his skin. The man was weak. Somehow, Shinji was more of a man than he was, which was a comfort. A comfort only in the sense that perhaps the boy might live long enough to father another useless generation of sycophants. With a hesitant voice, the boy began the chant.

"Fill Fill Fill Fill." Shinji said quickly. Mana provided by his crest worms filled the circle, mimicking a summoning. "This body be the gate, my mind be the Od of the transaction!" The rest of the ritual he borrowed from anime, some of the transformation sequences of the shows being akin to monster-animation activation rituals that were employed by shapechangers amongst the Ainu mages of old. There must have been a hint of power to them. Either way, there was nothing at stake here but mana. "From the Seventh Heaven, attended to by three great works of power; Come forth from the ring of restraints, protector of the holy balance!"

Zouken was not expecting anything to happen. He certainly wasn't expecting all of the mana in the room to suck into the circle, a blinding pillar of light cascading through the eternally dark room. A couple of the nearest worms were scalded by the magic, pure as it was. Zouken had one eyebrow raised at what remained in the circle. It was a woman. Not a girl, but a woman. She had hair to her ankles, a dress that Zouken considered fairly inappropriate, and a blindfold over her eyes. A cruel dagger on a chain hung from her belt. Her magic oddly fluctuated between the scent of a hero and that of a monster. Of course, all of that fled in an instant when the woman flailed and fell onto her ass.

"I can't see! Grandfather, help!"

It was still Shinji. He had stolen the body of a Heroic Spirit. He grinned madly. Progress indeed. "Just pull off the blindfold." Shinji pulled it off, eyes widening in abject terror as he looked down and saw what had occurred.

Overwhelmed, the now-Heroic Spirit Shinji screamed in shock and passed out. Zouken had just planned to leave them there and head upstairs, but Sakura ventured forwards. She was exerting all of her strength to take the changed Shinji back upstairs. To her room, it seemed like. "Congratulations, Shinji. You finally found a way to become sexually attractive to Sakura." He laughed more to himself than anything else. "Now I must find a way to distribute this information to Tohsaka. I can certainly ruin another generation of young mages with a botched ritual such as this. Especially if they die like Servants do at the end."

The first stop would be Rin Tohsaka. It would bring him such joy to cause her suffering. No one but that priest protected her. It would be a matter of ease to deliver the information. Or perhaps he could simply take some of the energy of the ritual and use his worms to move it to other potential masters. Yes, that would have the least risk.

One of his worms found a home in Rin Tohsaka's shower. A pseudo command seal was burned into her skin the moment she aggressively crushed it. Predictable.

Another he sent to Ryuudou Temple, to see what or who would be a good viable target here. He lost two of the marked worms to something in the old town district, but could confirm that the marks were placed. Along with the instructions for the new ritual, of course.

The remaining two worms he stored away from himself, the unstable magic within them not going to last long. He would have to find homes for them quickly. Perhaps he would just send them through the river and see who picked them up. It might be interesting.

Little did he know that Fujimura Taiga fell into the river that day.

[UwU]

"Kyaaa!" Rin shrieked, looking at herself in the mirror. The Mystic Codes she could handle. The giant floating lance? Great! Radiating waves of power and smoke from the mana? Awesome. "Blonde?!" She stared at the slightly cracked mirror in the main floor bathroom, at the heinous effect upon her hair. "Who in the name of God made me Blonde?!"

She would have gone on a further tirade, but there was a knock at her door. She wasn't expecting anyone. In fact, none of her wards were tripped. She should have gotten an alarm from one of them. But hey, at least she had a lance the size of her door to stab the offending party with. So she cracked open the door, and found the most curious sight. A woman wearing a dress that shouldn't be legal was kneeling on her doorstep, blue hair to her ankles.

"Who are you?" Rin asked, carefully. With all the powers of her current self, she could destroy this person with complete ease.

They looked up, and the face of Shinji Matou was framed by pretty hair and some kind of mark on his forehead. Of course the whole feminine look made them actually nice to look at for once. "Tohsaka! You were the only one I could turn to!"

"Matou." She said coldly. "You too, huh?"

"I barely escaped with my life!" Shinji yelled. "Sakura, she..." The miserable creature hiccuped. "She had whips and chains and I had to run! I had to escape!"

"Calm down, there. What's going on!" Rin found herself more patient with this body. For some reason she didn't want to stab Shinji. Yet. Perhaps watching him suffer was just too entertaining.

"Grandfather told me there was a ritual I could do to become a mage. Instead, I became this!" He held up his hand, where three glowing seals were present. "I heard him laugh and say your name, so I came as soon as I could escape the handcuffs!"

"Sakura has handcuffs?" Rin tried not to laugh. "Wait, wait, you can tell me later. Does this ritual state that the body is the gate?"

"Yes! That one!" Giant tears made their way down their transformed face. "How do we turn back to normal? I can't live like this!"

"If you want my help, you have to swear to me that you will not betray me. Swear that you would rather die than remain like this, and that you give up your right to victory in exchange for my ever-gracious mercy," Rin counted off, "and that you'll remain my servant until you graduate."

"Yes! Yes! Anything, I'll do anything! I swear!" One of the three glowing marks on Shinji's hand glowed and disappeared, as some kind of agreement was forged. "Wait, are those important?"

"To you? Not really. Now, come on in. Let's get you some clothes and we can figure out our game plan. If we want to win, we have to defeat five more Servants and then we should turn back to normal." Shinji wallowed on the front porch, unstable on their feet. "Come on, bondage barbie! Up those stairs!"

And so Rin Tohsaka and Shinji Matou worked together for once in their miserable lives.

[UmU?]

Shirou had no idea what Taiga brought home for him that night. It looked like some kind of fish. Or perhaps a kind of shrimp. She claimed she found it in the river, and who was he to complain about fresh fish? They kind of looked like worms, but Taiga was good with food. She always brought home good ingredients.

She had only found the two, oddly. The creatures fried very easily, and looked rather appealing on a plate. The moment that both of them took a bite, though, tragedy struck. Whatever these were, they were not fish. Both found themselves shuddering as the food hit their stomach, causing Taiga to leap over the table and run for the only bathroom in the house. He ran to the sink, trying to vomit but not achieving anything but dry heaves. Even these eventually relaxed, though, and his body seemed to stabilize. "Kami.." He muttered. "Taiga! Those were not fish!" He stomped his way over to the bathroom, but there was no one there.

Claw marks were on the walls, and some kind of scent came to his nose. A magical scent. That was when he felt something drip onto his shoulder. Looking up, he could only be completely surprised when he saw Taiga, clutching the ceiling with honest-to-god claws coming out of her hands. Her eyes were red and her clothes had changed.

"Surprise attack!" Taiga yelled, spitting into his face. Shirou fell back, screaming as Taiga took a swipe at him with her claws. His shirt suffered in the exchange, and he had to roll outside to avoid her next attack. "Bad cooking! You tried to poison the raging tiger!"

"You brought the bad food!" Shirou yelled, running out into the courtyard. "You should apologize!"

"The mighty Taiga never apologizes! Feel my wrath!" Normally when Taiga did one of her impromptu 'lessons' he could just block her. In this case, large furroughs were carved through the dirt. That wasn't normal.. From scent alone, this felt like magic. A curse of some kind. Of course, had he been more than just a crappy one trick pony, he probably could have fixed this.

"Taiga! Control yourself!" Telling her to control herself seemed to provoke a reaction, as she ran inside.

"I'm getting my beating stick, Shirou! Prepare yourself for the most instructive lesson of your short life!"

The shed. He needed to get into his shed. He ran, shirt tattered and broken. Whatever strange magic was coursing through Taiga, he could feel it too. His limbs ached and his magic circuits were burning. He slammed the door and twisted the bar, looking for anything that could help him. He ran towards the back of the shed, digging into the old boxes his father left him. He never noticed the symbol on the floor lighting up. "Come on, come on! Something in here can help!"

A voice carried through his mind. "You have called, and this soul has answered. You are looking for help?"

Voices in the back of his head were a bad thing, but the sounds of Taiga attacking his shed door were far more pressing. "Yes! I want to remove this curse from Taiga!"

"Then may my blade be the purging force of Nothingness to remove this from her. If you accept my help, hold out your hand and call for me."

There were marks upon his hand, magic ones. He had no clue what they did. "Who am I calling for?!" He demanded, his shed door denting as the crazed ramblings of his would-be older sister grew louder.

"I am Musashi." The voice said, giggling. "And I will help you save your friend."

Shirou could feel his tongue moving on its own, the magic infecting him becoming overpowering. "I summon you! Musashi!" He said, holding his hand out. As his door was finally battered down, the change hit him. His clothes were first, followed by a slight shift in perspective. In a single instant, his clothes had changed to a very short kimono. A sword was in his hand, and the blade felt more than real. The steel shone.

His eyes were drawn to Taiga's hand, where her own glowing symbols rested. "Trust my eyes. They guide you to the most direct path to victory."

Taiga leapt, her crude weapon coming at him at a speed that normally he could not have avoided. Instead, his eyes could see everything about Taiga's attack. Even how she had leapt slightly off balance on her left foot. The path ahead was so clear. It was so simple. Both blades flashed, and yet Shirou had his eyes closed. It felt so right. He was so confident that he even sheathed his sword. Behind him, Taiga fell to the ground with a groan, her odd outfit and claws fading away into flashes and motes of light.

"You are a perfect host, Shirou Emiya. My mind feels at peace with your own. Please use my gifts to your best strengths, for your heart is that of a true swordsman." The voice echoed. "Your friend will recover in time."

Shirou turned to face Taiga, but his body felt different. When he looked down, he could see a very unfamiliar form. "What is this?!"

"My body. You wanted my help? You have summoned my form and skills." The voice said. "Please take care of me."

"So, did you stop Taiga or did I?" He didn't care if he looked like a girl. There were plenty of weird media about this. Shirou wouldn't let it stop him from doing what needed to be done.

"Though you have my body and skills, the decision to use them and the power behind them are yours. Though my skills are great, they are only powerful in the hands of someone capable of using them."

Shirou flexed the slim hands. Belying their appearance, they held great power.. "Teach me, then. Musashi-Sensei." If this was some kind of trick, it was cruel. But so long as he had this power, he was going to spend every waking moment learning from it. This power was his, if she were right. The power of Musashi. "So you trust me, even to this extent?"

"I will teach you how to be the most powerful swordsman the world has ever seen, or my name is not Shinmen Musashi."

"Musashi-Sensei." Shirou bowed, the feelings unfamiliar. "How do I turn back?" The voice in his mind giggled and mumbled some kind of wording. "Forever?! What do you mean this is permanent?!" Only ghost-like giggling answered him.


End file.
